2003 ford forcus radio

While setting a preset station on my radio, the channel set then the radio started turning on and off on and off etc. etc. It will do this even with the car parked and the key out. What can I do to make it stop and will it hurt the battery.

Any drain can hurt the battery. You need to determine if it is only the radio going on and off. If other circuits not normally active when the car is off are live you have a bigger problem than just the radio. If it is only the radio you can pull that fuse. Check to see heater fan, gauges, and other components are normally off stay off. My guess is they are not pointing to a possible ignition switch problem.